If you want to read your favourites PDF or ebook on your nokia handset you need some ebook reader application to do that, the one that i recommend is Qreader, this freeware compatible for Nokia 5800,  N97, and Samsung i8910 Omnia HD, i’ve install it to my Nokia 5800 XpressMusic and it works properly, see some features of Qreader below:

* Plain text (.txt), Palm DOC (.prc and .pdb), TCR, FB2 and UMD files reading
* Incoming document recognizing
* Screen rotation (90, 180 and 270 degrees)
* TTF scalable fonts support
* Folders support
* Hi-Quality Bookmarks
* Auto-scrolling
* Text Formatting
* Hyphenation support
* Search (case-sensitive and caseless)
* Percentage indication of the text that has been read
* Easy access to clock
* Adjustable colors
* Adjustable document locations
* Send any text file via Ir, Bluetooth or Email
* Function of backlight switch off while reading can be turned off
* 60 different character’s codepages + 3 Unicode.

Download Qreader – ebook reader for your Nokia N97 and Nokia 5800 Here